1. Field of the Invention
The invention relates to an evaporative fuel treatment apparatus.
2. Description of Related Art
There is known an existing evaporative fuel treatment apparatus in which a partition wall is provided inside a fuel tank, a small fuel storage chamber is defined by the partition wall inside the fuel tank, a canister is accommodated in the small fuel storage chamber, the canister is cooled by introducing fed fuel into the small fuel storage chamber during refueling, and the canister is heated by introducing high-temperature returned fuel into the small fuel storage chamber during engine operation, thus facilitating the fuel adsorption action and fuel desorption action of the canister (for example, see Japanese Patent Application Publication No. 64-000347 (JP 64-000347 A)).
However, in the existing evaporative fuel treatment apparatus, the amount of fuel inside the small fuel storage chamber depends on the amount of returned fuel, the area of an opening portion of the small fuel storage chamber which serves as an overflow passage between the small fuel storage chamber and the inside of the fuel tank, and the area of a small hole that communicates the small fuel storage chamber with the inside of the fuel tank.
Therefore, the existing evaporative fuel treatment apparatus is not able to adequately adjust the temperature inside the canister (hereinafter, also referred to as “adsorber”), so there is an inconvenience that it is not possible to sufficiently exercise the evaporative fuel adsorption performance and adsorbed fuel desorption performance of the adsorber.